Light socket



July 10, 1928. 1,677,114

o. s. FIELD LIGHT SGCKT Filed April 6. 1921 lll/7M Kimm" Patented July l0, 1928.

UNITED STATES PATENT oFFICE. y

`OSCAR S. FIELD, OF ROSELLE, NEW JERSEY, ASSIGNOR, BY MSNE ASSIGNMENTS, T UNION SWITCH & SIGNAL CO., OF SWISSVALE, PENNSYLVANIA, A CORPORATION OI' FENNSYLVANIA.

Application led April 6,

This application relates to certain improvcments in sockets tor electric lamp bulbs and particularly that kind known as the bayonet cap type.

he particular object ot the invention is to provide a socket which will correctly align the bulb and eliminate rocking on the pins of the lamp case, which is a defect common to sockets which are now commercial.

A further object of the invention is to provide means whereby the filament ot' the ulb is accurately aligned in a definite position, such as in the focal point of a reflectorl or lens.

Another object is to provide a. socket which may be adjusted, in order to focus the "same, together with means whereby any subsequent bulb placed in the socket will automatically assume a correct location.

Further objects of the invention will be apparent from the accompanying description and appended claims.

Fig. 1 shows a side elevation of the socket with a bulb inserted therein.

Fig. 2 is a rear elevation ot the same.

Fig. 3 is a Section through the socket with the bulb removed.

Fig. 4 is a plan View ot' the socket and bulb.

It will be apparent that while these figures disclose one particular form of construction of the apparatus the construction may be modified without. departing trom the spirit of the invention.

In order to be sure of the correct align ment ot the filament and the interchange ability of the bulbs, all bulbs to be used with the socket are tiret of all correctly mounted in their base in such a manner that the fila- 40 ment 1 is accurately located in relation to the bayonet cap pins 2. This may be done in various manners and does not constitute a part of thi" invention. Pins 2 are accurately located in the base 3 and are displaced 45 from one another by an angle ot' 180O thereby placing the pins an equal distance from the upper and lower sides olf the base 3 when viewed 'troni the plane shown in Fig. 1 so that the pins 2 will always assume a position 50 on a horizontal axis of the base irrespective ot' which way the bulb is inserted in the socket.

The socket comprises a metal shell 4 which LIGHT SOCKET.

1921. serial No. 459,199.

has a forward extension 5 which .is cut away at 6, leaving the shell at this part open. lat is further provided with oblique slots 7 and 8 adapted to take the bayonet cap pins 2. This shell is turni'hcd with an insulating member 9 which is adapted to carry springr pressed contact studs 1() and 11 of a type well-known in the art. By referring to Fig. 3 it will be seen that the contact stud 10 is located slightly in advance ot the contact' stud 11, the purpose of which will be explained hereafter. i

The shell 4 is further provided with a keyway 12 and is tapped atl in order to i take the adjusting screw 14. The side ot' the shell is cut away at 15 to provide an outlet Jfor the leads 16 and 17. which are connected to the contact studs 10 and 11 respectively. This shell 4is adapted to slide in a tube 18 of insulating material which is carried in the supporting member 19 which may be a part of the body ot the lamp or other device in which the light is used. A key 20 ot insulating material is provided whicih is adapted to .tit into a rece-"s formed in the supporting member 19, thc object ot' this key being to prevent rotating of the shell4. The screw 14 is adapted to pass through insulating bushing 21 and a spring' 22 is provided whieh presses against the end ot' shell 4 and is insulated from the supporting' member 19 by means ot a washer 23 ot insulating material.

It will be apparent from this construction that upon rotation of the screw 14, the shell 4 will be moved forward or backward in ac cordance with the direction ot' rotation, thereby comprising means tor a horizontal adjustment of the shell which forms the light carrying member.

The operation of the device is as follows y In order to insert a bulb the pins 2 of the bulb are laid upon the flat surfaces 24 of the cut away section 6. The bulb is then forced backward against the pressure of contact studs 10 and 11 until the pins pass olf the surfaces 24 when they are forced down in the oblique slots 7 .and 8. Upon release of pressure from the bulb it is apparent that the contact springs 10 and 11 will force the bulb forward, forcing the pins 2 into intimate contact with the oblique surfaces 25 and 26 of the slots 7 and 8. Owing to the horizontal pressure exerted upon the bulb and the angle of the slots at the surfaces 25 and 26, the pins 2 will be caused to travel down the oblique surface until the base`3 is brought into intimate contact with the inner surface 27 oi the shell 4. On account of the upper stud l() being arranged slightly in advance of the lower contact stud 1l it will be apparent thatthcre is a tendency for the bulb to be tilted in a downward direction, thereby insurineY base 3 remaining in intimate contact with the inner surface 27 throughout its Whole length.

From the above description it will be seen that when a bulb is inserted in the socket `it will automatically assume a definite position determined by the inner surface 2T ot the shell 4, and the bayonet cap pins 2 in the slots 6 and 7.

It will further be seen that all tendency for the bulb to rock about the pins 2 has been eliminated, due to they fact that the base 3 has been brought into this intimate contact with surface 27; and because the filament l is in accurate location in relation to the pins 2 on the base 3, the filament will assume a definite pre-determined position in relation to the socket. It will further be seen that in View of all bulbs being, based with the filament accurately located in relation to the pins. that `any bulb may be inserted in the socket with the assurance that the filament will accurately assume its cori rect position. Y

It is further apparent that with the construction disclosed the shell 4 which comprises the lamp socket is completely insulated from the supporting member 19 and that after the socket has been adjusted the recess 28 may be lilled with any desirable sealing compound, thereby preventing the socket being changed in its adjustment.

What I claim isz- 1. In a light socket for cri-operation with an electric bulb having a bayonet base, a socket member open at one side and having oblique slots formed therein to receive the pins of the lamp base, and a spring pressed contact stud insulatively mounted therein, whereby upon pressure being exerted by the contact stud the base of the bulb is forced forwardly and transversely into intimate contact with the walljof the socket member to align the bulb in two planes.

2. In a light socket tor cooperation with an electric bulb having a bayonet hase, a socket member open at one side and having oblique slots formed therein to receive the pins of the lamp base, and spring pressed Contact studs insulatircly mounted therein one being slightly in adifance of the other. whereby upon pressure being;r exerted by the contact studs the base ol the bulb is forced forwardly and transversely into intimate Contact with the wall of the socket member to align the bulb in two planes.

In testimony whereof, I have signed my name to this specification.

OSCAR S. FIELD. 

